sql server programming: Add the column, run an update statement:

create table tablename
(
x int
)
insert into tablename values (1)
insert into tablename values (2)
insert into tablename values (3)
go
alter table tablename add y int null
go
update tablename
set y = x+3
go
alter table tablename alter column y in not null
go

Will you want all new values to be x + 3, or just initially? If the ONLY
values ever to be stored would be then you can use a computed column and
index it (this will persist the values so it doesn't have to be calculated
except the first time:

alter table tablename add y1 as (x+3)

create index tablnamePersistY1 on tablename(y1)

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[quoted text, click to view]

What's the best way to add a new column Y to an existing table that already
has existing column X, and I want Y to be x+3? I need to actually save the
value in the database, so yes, I do want a new column.

[quoted text, click to view]

Hi AFN,

ALTER TABLE MyTable
ADD Y AS x+3

Best, Hugo
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